When cooking food by heating it with a general cooking appliance, the food is weighed by a balance or the like, and, based on the measured weight, the heating time and the heating output are preset by the use of a rotary timer or output setting keys and so forth. This requires troublesome operations such as, particularly, weighing, setting of the timer and the heating output, etc. before starting the cooking operation and therefore an improvement which will permit easier operation has been desired.
Further, recently, there have been developed automatic cooking appliances equipped with an infrared ray sensor for detecting the surface temperature of the food and a humidity sensor and a gas sensor for detecting water vapor, alcohol, etc. produced from the food to detect the heating condition and the cooked state of the food, thereby effecting automatic cooking. However, with such an automatic cooking appliance, the sensors detect mainly the heating condition of the surface of the food. For this reason, the cooking condition varies depending on the weight of the food, and, especially when the food occupies a large volume, there occurs a great difference in the temperature between the center portion and the surface of the food, thereby giving rise to a variation in the cooked state of such food.
Improvements in this respect have been necessary, and, to serve this purpose, automatic measurement of the weight of the food has been desired
The invention (Japanese patent application No. 44286 of 1982), which the present inventor made to attain the aforementioned purpose, was directed to a high frequency heating device in which vibrating means using a spring is provided on a turntable which rotates with food placed thereon, and the weight of the food is detected by transmitting the vibration of the vibrating means to the outside of the heating chamber by means of magnetic coupling so that, in accordance with the weight of the food thus detected, the output from the high frequency oscillator and the heating mode and the heating time are controlled. However, it was necessary to improve the above-mentioned device to elevate its performance.